Fix testSocketKeepaliveLimitTelephony on R

DEVICE_INITIAL_SDK_INT does not exist in older SDKs: use the pre-rename
field, FIRST_SDK_INT instead.

Fixes: 185731191
Test: atest ConnectivityManagerTest#testSocketKeepaliveLimitTelephony
Ignore-AOSP-First: Needs cherry-picks

Change-Id: I1fbc0f714d539a664c053cb9cf1f86c3e651c5a2

tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java

@@ -131,6 +131,7 @@ import androidx.test.InstrumentationRegistry;
 import androidx.test.runner.AndroidJUnit4;
 
 import com.android.internal.util.ArrayUtils;
+import com.android.modules.utils.build.SdkLevel;
 import com.android.networkstack.apishim.ConnectivityManagerShimImpl;
 import com.android.networkstack.apishim.common.ConnectivityManagerShim;
 import com.android.testutils.CompatUtil;
@@ -1418,7 +1419,10 @@ public class ConnectivityManagerTest {
             return;
         }
 
-        final int firstSdk = Build.VERSION.DEVICE_INITIAL_SDK_INT;
+        final int firstSdk = SdkLevel.isAtLeastS()
+                ? Build.VERSION.DEVICE_INITIAL_SDK_INT
+                // FIRST_SDK_INT was a @TestApi field renamed to DEVICE_INITIAL_SDK_INT in S
+                : Build.VERSION.class.getField("FIRST_SDK_INT").getInt(null);
         if (firstSdk < Build.VERSION_CODES.Q) {
             Log.i(TAG, "testSocketKeepaliveLimitTelephony: skip test for devices launching"
                     + " before Q: " + firstSdk);